Fossil of a giant ant found in North America

The fossil of a gigantic ant, similar to ones that lived 50 million years ago in Europe, hasbeen found for the first time in North America.

Some scientists believe it isa new species.

The winged queen ant collected in the Green River Formation in Wyoming is "about the size of a small bird about the body mass of a small bird as well," said Bruce Archibald, the Simon Fraser University researcher who identified it."It's pretty impressive."

Archibald, who specializes in studying fossil insects, is lead author of a paper about theant published this week in Proceedings of the Royal Society B.

The fossil had spent some time in a drawer at theDenver Museum of Nature and Science inColorado, where there were no fossil insect experts available to look at it.

When Archibald visited the museum, curator Kirk Johnson decided to take advantage of his expertise and showedhim someunidentified specimens.

Archibald realized one of them closely resembled giant ant species that lived in Germany during the same period, the Early Eocene.

No such whole fossils had been found in North America before,although afossil wing, belonging to a different species,had turned upin Tennessee, Archibald said.

ThenewNorth American species was namedTitanomyrma lubeiand is believed to be closely related to the German giant ant species.

The climate in both Germany and Wyoming during the Early Eocene was hot and steamy "like the kind of heat you'd find today in Panama or Central America," Archibald said.

The similar fossils on both sides of the Atlantic suggest giant ants somehow travelled between Europe and North America.

On one hand, that was plausible because there was a land bridge near Greenland connecting the two continents. There was just one problem it wasn't very hot there.

"The mystery is how [they] could have passed through this temperate climate region," Archibald said.

A closer examination of climate patterns in the Arctic shows that there were brief periods of global warming during the Early Eocene when the climate may have reached tropical temperatures.

"A physiological gate of climate could have opened periodically and allowed tropical adapted organisms to pass between continents," Archibald said.

Similarly, he said, recent reports of dragonflies in northern Canada, where they haven't been seen before, suggests that insects can expand their ranges in response to climate change in a very short amount of time.